JPH02274139A - Data transmission system - Google Patents

Abstract

PURPOSE:To superimpose a clock on an NRZ code by superimposing pulsive recessed section onto the data of level 1 of an NRZ code at a transmission section and superimposing pulsive projecting sections onto the data of level '0'. CONSTITUTION:In the case of transmitting the data as the NRZ code, a pulsive clock pulse is synthesized with the NRZ code and a transmission signal as shown in figure is generated and transmitted. In this case, a recessed section A having a width corresponding to the clock pulse is formed with respect to the data of a level 1 and a projecting section B having a width corresponding to the clock pulse is formed to the data with a level 0. Thus, in the reception section, the rising point in the transmission signal is extracted to generate the clock.

Description

[Detailed Description of the Invention] [Summary] This invention relates to a data transmission system that transmits data given by NRZ code.

The purpose is to enable a clock to be superimposed on the NRZ code.

The transmitter is configured to superimpose a pulse-like depression on data with a value of "1" of the NRZ code, and superimpose a pulse-like protrusion on data with a value of "0" of the NRZ code.

[Industrial application field]

The present invention relates to a data transmission system that transmits data given in NRZ codes.

In wired transmission systems using coaxial lines, optical fibers, etc., there are demands for higher transmission speeds, smaller equipment, and lower power consumption.1 To achieve this, it has become necessary to simplify the circuit configuration. There is.

(Prior Art) Generally, in digital transmission, it is necessary to transmit a clock as well as data. In the conventional case, N
A method is adopted in which the original code of RZ is converted into a CMr code, AMI code, etc., and then sent to a transmission path.

[Problems to be Solved by the Invention] In the above conventional case, since CMI symbols, AM, and I codes are used, the circuits of the encoder in the transmitter and the decoder in the receiver are complicated. Ta.

The present invention aims to solve this problem by making it possible to superimpose a clock on the NRZ code.

[Means to solve the problem]

FIG. 1 shows a diagram explaining the principle of the present invention.

In the case of the present invention, 1. When transmitting data given by an NRZ code as shown in the figure, a pulse-like signal is combined with the NRZ code. L7-1 generates and transmits a transmission signal as shown in the figure.

[Function] In the case shown in Figure 1, a recess A having a width corresponding to the clock pulse is created for data (ii'l), and for data of value "0". 1 A protrusion B is created with a width corresponding to one clock pulse.

Therefore, in the receiving section, it is possible to extract the rising point of the "transmission signal" shown in FIG. 1 and generate a clock based on this.

[Example] FIG. 2 is an explanatory diagram of a transmitting section, where FIG. 2(A) shows the configuration of the transmitting section, and FIG. 2(B) shows waveforms at points shown in FIG. 2(A).

Reference numeral JO in the figure is a transmitter, 11 to 16 are husband-h frimb flops, 17-1. 17-2 represents an AND circuit, 18 a NAND circuit, and 19 an OR circuit. Also, points 1■,■,■ in the figure.

2 corresponds to the illustration in FIG. 2(B).

Assume that NRZ code data as shown in Figure 2 (13) is supplied to the D terminal of the flip-flop 11. Second
Diagram (B) "Clock human power" with the data shown in the diagram
is supplied to the flip-flop 13, and a "1x clock" having a frequency n times higher than the "link input" is supplied to the flip-flop 13.
is supplied to each flip-flop 11-16.
Although the illustrated case represents the case where n=4, it is desirable that n take a larger value.

The point is calculated by taking into account the delay of one pulse in the 0x clock.■
The waveform at point (2) rises, and the waveform at point (2) falls with a width of one pulse.

Further, the waveform at point (2) falls with a delay of one pulse in the 0x clock, and the waveform at point O rises with a width of two pulses.

Using the waveforms at points ■ and ■ obtained in this way, and the waveform at point ■ which was delayed by two pulses.

By performing the AND-OR logic, a waveform of two points (2) is obtained, which is then shaped by the flip-flop 16 to obtain a transmission signal as shown as a waveform of one point (2).

FIG. 3 is an explanatory diagram of the receiving section, with FIG. 3(A) showing the configuration of the receiving section, and FIG. 3(B) showing waveforms at points shown in FIG. 3(A).

In the figure, 20 is a receiving section, 21 is a flip-flop,
22 is a delay circuit, 23 is a NOT circuit 24 is an AND circuit,
25 is a filter, and 26 is a rectangular wave generation circuit.

Note that the delay circuit 22, NOT circuit 23, and AND circuit 24 shown in FIG. 1 form a differentiating circuit.

Assume that an input signal as shown in the figure is given. Corresponding to the falling edge of the human input signal, the pulse and (
It will be done. The pulse is supplied to the filter 25 to generate a sine wave as shown in the waveform at one point (2), and the rectangular wave generation circuit 26 generates a rectangular wave having the duty as shown (waveform at point (2)).

The input signal is sent to the flip-flip 21 using the falling point of the rectangular wave shown as the waveform at point 2. That is, 1
In the illustrated case, data rl, 0.00.1...'' is decoded.

〔Effect of the invention〕

As explained above, according to the present invention, the circuit configurations of the transmitting section and the receiving section are significantly simplified.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of the principle of the present invention, FIG. 2 is an explanatory diagram of a transmitter, and FIG. 3 is an explanatory diagram of a receiver. The symbol IO in the figure represents a transmitter, and 20 represents a receiver.

Claims (1)

[Claims] A transmitting unit (10
) and a receiving unit (20) that receives the data, in the transmitting unit (10), synthesizing a pulse-like clock pulse with the data given by the NRZ code, For data with a value of "1", a recess with a width corresponding to the clock pulse is formed in the data, and for data with a value of "0", a recess with a width corresponding to the clock pulse is formed in the data.
It is configured to send out a transmission signal in which a convex portion with a width corresponding to a pulse is formed, and the reception section (20) extracts a falling point of the received transmission signal and clocks it. A data transmission system characterized in that the data transmission system is configured to generate a clock and decode the received transmission signal based on the generated clock.